Photogalvanic effect in few layer graphene

TL;DR

This study explores the nonlinear photogalvanic effect in various few-layer graphene structures, revealing symmetry-dependent behaviors and potential applications in tunable photodetectors and energy harvesters.

Contribution

It provides a comprehensive analysis of shift and jerk currents in layered graphene, highlighting the role of stacking order and symmetry in nonlinear photocurrent generation.

Findings

Nonvanishing shift current occurs only in ABA-stacked trilayer graphene due to broken inversion symmetry.

Jerk current is present in all structures and is highly tunable with chemical potential.

Peak shift current conductivity reaches approximately 1.21×10⁻¹³ A·m/V² at optimal doping.

Abstract

We systematically investigate the nonlinear photogalvanic effect in few-layer graphene with various stacking orders, including AA- and AB-stacked bilayers, and AAA-, ABA-, and ABC-stacked trilayers. Using a tight-binding model to describe the electronic states, the shift current conductivity and jerk current conductivity are calculated over a broad spectral range from terahertz to visible frequencies. Our symmetry analysis reveals that a nonvanishing shift current emerges only in ABA-stacked trilayer graphene due to its broken inversion symmetry, with a peak conductivity reaching approximately $1.21 \times 10^{-13}$ A$\cdot$m/V$^2$ at optimal doping. In contrast, the jerk current, permitted in all structures, requires an in-plane static electric field and exhibits pronounced spectral tunability with chemical potential. These findings establish a comprehensive symmetry-band-field coupling paradigm for nonlinear photocurrents in layered graphene and provide design principles for tunable, polarization-sensitive photodetection and energy-harvesting devices based on van der Waals heterostructures.